Blades used in tools such as electric grinders or sanders are utilized in a variety of applications where precise control of the tool may be required. Such applications include shaving mortar or concrete adhering to old bricks, tiles, concrete or frames, and have the objective of removing such foreign matter from the substrate evenly and completely without damaging the substrate. The precise type and size of blade used varies depending upon the circumstances, including the nature of the substrate and its construction, i.e. whether it is a wall, ceiling or floor, as well as the nature of the material to be removed. Thus, the blades may take a variety of diameters and thicknesses and may have various edge treatments and configurations.
Conventional portable power tools to which such blades are affixed have a rotating axle or arbor for mounting the blade. Auxiliary elements, such as a shroud or dust shield, may be part of, or affixed to, the tool for dust collection and to provide protection against inadvertent contact with the rotating tool element. Because the tool arbor is generally of a fixed length, the mounting of a blade thereon may not be optimal with respect to the position of the hood or shroud. Improper alignment between the tool and shroud may compromise tool safety, or may affect the efficient use of the tool. Because the mounting arbor is fixed, and the blade is normally installed fully upon the arbor, the blade periphery may not be properly aligned with the shroud.
It is accordingly the purpose of the present invention to provide a blade mount or coupler which allows a blade of a power tool to be properly positioned with respect to auxiliary equipment associated with the tool, such as a hood or shroud.
A further purpose of the present invention is to provide such a coupling that minimizes the projection of the coupling shaft beyond an adjacent blade portion to minimize interference between the shaft and the work.
Still a further purpose of the present invention is to provide such a coupling which can accommodate a variety of blade sizes and shapes, and can be utilized with a variety of power tool constructions.